The purpose of the research is to examine and evaluate electrophysiological measures which are related to the developing sensory, perceptual and cognitive processes of infants and young children. The general method is that of recording of computer averaged evoked EEG responses to visual and auditory stimuli in normal children and in children with abnormalities of sensory and mental development. The relationship between sensory evoked potentials, electroencephalographic, behavioral and biochemical parameters of development are being examined. The applications of evoked response recording to clinical diagnosis, i.e. in children with sensory, mental, and perceptual abnormalities, are being investigated and evaluated. The method is being applied as a tool in audiologic diagnosis. Research on the EEG and evoked potentials in patients with Down's syndrome, degenerative CNS diseases of early childhood, cortical blindness, and malnutrition is being done. The research will provide basic data on the maturation of the EEG and sensory evoked potentials of human infants during the course of development and will attempt to relate data obtained from psychological and neurological testing with the neurophysiological data. It will provide normative data for comparison with that obtained from patients with sensory and neurological handicaps.